Claire Armitstead on securing bikes

Ten days ago I nearly became a crime statistic. It happened on a Saturday, some time after I dropped my daughter off at music school, leaving her bicycle chained to railings outside. When I went back to collect her, the bike was gone, the only trace of it a dead-looking cable lock, cleanly severed at the throat.

For the 20 murderous minutes of my bike ride home, after begging a lift for my daughter from one of the car-driving mums, I would have mugged anyone I saw in possession of our missing bike. I thought of reporting it to the police, but to do so in my part of London would involve spending a sunny Saturday afternoon in the bowels of the local station.

When we checked the house insurance, there was a £100 surcharge. How much was the bike worth anyway? It had been in the family so long, passed from child to child, that it was practically an heirloom. So we decided not to report it, which means that it will not be among the 480,000 or so bikes that, going by Home Office figures for 2006-07, will be officially stolen in Britain this year.

I briefly considered following the example of a family I know by sending a large teenage boy down to London's Brick Lane market on Sunday morning to buy another. Who knows, it might even be the same bike. Then my better instincts kicked in. To buy one without knowing its provenance would only fuel the local black economy that thrives on the theft of bicycles parked outside schools. And anyway, there's nothing my partner likes better than perusing bike websites. So I left dad and daughter in front of the computer and went off to brood about where it had all gone wrong.

It didn't take long to work out. The lock was so puny that any chancer looking to finance a night on the town could see it would cut like cocaine. If we were going to invest in a new bike, we also needed to invest in better security. But how do you choose a good lock?

First port of call was the WhyCycle website, which gives independent advice on all sorts of cycling issues. Its section on locks reads like an S&M catalogue: cable, chain and armoured, shackle or loop. Some of its conclusions are equally hardcore: "Consider a range of locks, each catering for the different locations you will need to leave your cycle." Well, I'm sorry, but it ain't going to happen.

Generally, though, it gives useful tips: for instance, police suggest you spend 10% of the value of your bike on a lock to secure it. Don't be fooled by cheap ones that look really beefy. Most locks in shops are sold with a security rating, but I've spent enough time grappling with the vagaries of dress sizes to know that this works only if you are familiar with the brand involved. WhyCycle is helpful here - the accreditation scheme "Sold Secure" tests new locks, logs the time it takes to break into them with a range of implements, and awards them a standardised gold, silver and bronze ratings.

But this doesn't help me on the type of lock, so I phone the Manchester-based Bicycle Doctor co-op. "We recommend D locks, because cables can always be cut," says Rich, described in his biog as "a regular participant in 24-hour mountain bike racing and frequents the challenging trails of [Spain's] Sierra Nevada mountain range with a loose anarchist collective of similarly obsessive bikey mates." Clearly a man you can trust.

Lock sorted, I consider security tagging. This takes me to Bike Register, run by family-owned security firm Selectamark, which boasts 500,000 members on a national registration scheme accessible to police forces nationwide. For £5.95 you register for life and get a holographic label; for £10.95 you get a visible marking kit with your registration; and for £20.95, you can augment these with an electronic datatag to plant inside your bike frame. Brick Lane market may never be the same again.